Over the past two decades, the meteoric rise of the personal computer has transformed the world. A recent report in Forbes notes that over 100 million personal computers were sold in 1998 alone. In just the past few years, the ability to connect all of these millions of computers dispersed across the globe through the World Wide Web has sparked a huge increase in the amount of information that is conveyed and business that is conducted on-line. A recent study conducted by the University of Texas and published in Fortune indicates that the U.S. Internet industry collected $300 billion in revenues in 1998, nearly as much as the American automotive industry.
Many experts in the telecommunications business believe that a new and even more dramatic phase of this communications revolution is about to unfold. Although millions of additional personal computers will continue to be added to the Internet, many new electronic devices will soon be connected in extensive networks for the first time, In his 1998 book entitled New Rules for the New Economy, Kevin Kelly estimates that there are currently six billion “chips in objects,” other than those in computers, which are currently in operation around the world. Televisions, household appliances and lighting components, heating and cooling systems, security alarms and office equipment are all capable of being controlled or monitored by signals transported through network connections. Even the most prosaic appliances that utilize simple, single-purpose chips can be monitored or controlled by network signals.
One of the most serious drawbacks of trying to connect many devices in a network using conventional hardware is the need for cables, interface equipment and connector terminals. This is especially true in situations where wires are exposed in interior living or working spaces because they have been added after interior construction has been completed. A profusion of wires draped from a desk and tangled on the floor is an eyesore, and in some instances, a safety hazard.
One recent improvement has been the introduction of a limited number of devices that include wireless transmitters and receivers. Many printers, laptop computers and personal digital assistants use infrared ports to exchange data with computer systems. These infrared units have very limited range, and generally require a line-of-sight to their targets.
A number of new companies are attempting to develop wireless network systems. A new venture called OpenSky has been formed by 3C and Aether Technologies Bluetooth™ is a cooperative effort of several telecommunications companies seeking to establish a standard for wireless connectivity in the 2.45 GHz band. Home RF™ is a proposed wireless system offered by Microsoft™, Home Wireless Networks™ also plans to offer wireless networking products.
When radio waves are employed to connect devices in the United States, the manufacturer of the radio devices must be sure to operate within specific frequency bands and power limits prescribed by the Federal Communications Commission (FCC). The FCC allocates and coordinates the utilization of the Radio Frequency (RF) bands to ensure that interference among many different users of the spectrum is minimized. Some of the frequencies allocated by the FCC are situated in “unlicensed” bands, meaning that the use of these frequencies does not require the formal grant of a license from the FCC. Part 15 of the Code of Federal Regulations contains regulations which permit unlicensed radio transmissions if the transmissions meet many guidelines pertaining to power levels, antenna size, distance and other factors.
These complex government regulations present a serious obstacle to the development of any type of new wireless network, A wireless network may not be operated in frequency bands that are already licensed to other users, and may not operate in an unlicensed band unless it meets the stringent requirements of Part 15.
The problem of providing a high-speed, easily expandable and flexible network for linking many diverse devices and appliances has presented a major challenge to engineers and technicians in the communications industry. The development of methods and apparatus that could easily connect many different devices simply, at a relatively low cost, without wires and without causing interference to other users of the radio spectrum would constitute a major technological advance in the telecommunications business, and would satisfy a long felt need within the electronics and computer industries.